A typical antifriction bearing as described above is widely used as a radial ball bearing, cylindrical roller bearing, needle roller bearing, and so on. For example, often used in vehicles are antifriction bearings which are arranged between a rotor rotatably driven by the driving force of the engine and a housing supporting such rotor, and which rotatably support the rotor in the housing. As an example of a rotor which is rotatably driven by the driving force of an engine, there is a torque converter, and, for example, Japanese Patent Laid-Open Publication No. Hei 11-2298 discloses a belt-type gearless drive mechanism comprising a torque converter on the input side of the transmission.
A torque converter is a hydrodynamic power transmission device disposed between the engine and transmission, and transmits the rotational driving force of the engine to the transmission. A representative cross section thereof is as shown in FIG. 7, and comprises the principle structural elements of pump impellers (hereinafter “pumps”) arranged to face each other in a converter case filled with hydraulic fluid; a turbine runner (hereinafter “turbine”); and a stator 133 disposed between the turbine outlet and the pump inlet. The pumps are connected with bolts to a drive plate 136 of the engine output shaft Es (crank shaft) together with converter cases 134 (134a, 134b) to which a pump impeller 131 is fixed, and are integrally and rotatably driven together with the drive plate 136 by the rotation of the engine output shaft Es. The turbine is spline-engaged to the input shaft 20 of the transmission with a turbine runner hub 132a connected to the turbine runner 132.
A pump impeller hub 131a is integrally connected to the bore side of the converter case 134 to which the pump impeller 131 is fixed, and the pump is rotatably and axially supported by a radial ball bearing 112 disposed between an engagement shaft formed around the outer periphery of the pump impeller hub 131a and a bearing housing formed on the bulkhead 111 of the transmission case. The drive gear 192 of the hydraulic pump for generating hydraulic pressure necessary for transmission operation and lubrication of the respective components is disposed adjacent to the bearing engagement of the pump impeller hub 131a. 
With the torque converter 130 as constituted above, the pump impeller 131 turns pursuant to the rotation of the engine output shaft Es, and the hydraulic fluid filled internally is force fed from the outlet of the pump periphery to the inlet of the turbine runner 132 periphery. The force fed hydraulic fluid pressurizes the turbine runner 132 and turns the turbine, and rotates the spline-engaged transmission input shaft 20 with the integrally connected turbine hub 132a. The stator 133 is connected to the bulkhead 111 of the transmission case via a one-way clutch 137 and a shaft member 140, and rectifies the dynamic pressure of the excess hydraulic fluid in the turbine 132 and supplies this to the pump 131 in order to increase the pump torque.
Nevertheless, with the aforementioned conventional antifriction bearing, generally, the width of the inner ring and outer ring, which sandwiches and relatively rotates the rolling element, in the rotation axis direction is formed in approximation, and the back face engaged with and supported by the bearing can only be provided to the two faces; namely, the engagement face on the inner periphery of the bearing and the engagement face on the outer periphery of the bearing (in other words, the shaft side engagement face on the inner periphery of the inner ring and the hole side engagement face on the outer periphery of the outer ring). Thus, members capable of being supported by the bearing were limited to the shaft-side member (aforementioned pump impeller hub 131a for example) to be engaged with the inner periphery of the inner ring and the hole-side member (aforementioned bulkhead 111 of the transmission case for example) to be engaged with the outer periphery of the outer ring, and it was not possible to support members other than those described above.
Therefore, as with the drive gear or drive sprocket which drives the hydraulic pump, upon attempting to support a rotation member which is arranged on the same axis as with the rotation axis of a rotor and rotates in the same manner as with the rotation axis, it is necessary to provide an engagement member for engageably supporting the rotation member to the rotation axis side, and there is a problem in that the structure of the rotation axis becomes complex. Moreover, upon supporting the rotation member with only a spline engagement and without providing an engagement member as described above, there is a problem in that clearance between the male and female spline would rattle, thereby causing vibration and noise from the engagement. This type of problem does not only concern the axis side but also extends to the hole side, and, for example, there is a problem in that the housing structure would become complex when the outer ring is rotatably driven or when attempting to provide an axis seal member or the like on the same axis in relation to the rotation axis.